The authorities are expected to launch a major drive to clean up the effluent-ridden Yamuna and overhaul the city's doddering drainage system in a bid to spruce up the Capital ahead of the 2010 Commonwealth Games. Officials claimed the discharge of untreated effluents into the river was the main cause of water pollution and as such a plan was being drawn which to ensure that no untreated effluent was discharged into the water body. One of the focus areas of this programme is the installation of systems to intercept sewage on the three major drains of Delhi, the Najafgarh, Shahdara and Supplementary drains.